Planar sleeve antenna for low-band UWB system

In this paper, the planar sleeve antenna exited by the CPW is analyzed from the standpoints of return loss characteristics and radiation characteristics. The sleeve antenna is printed on the dielectric plate and three planar sleeves are located outside of the CPW. The open ends of three sleeves are aligned on the same position of the CPW and three sleeves are attached on the upper radiator extended from the central conductor of the CPW. From the calculated current distribution on the CPW, the leakage current on the CPW flowing from the sleeve radiator is investigated. The design frequencies of three sleeves are 3.5 GHz, 4.0 GHz and 4.5 GHz. The effect of sleeves is discussed from the calculated current distribution on the antenna and the radiation patterns.